Method of making a slide-fastener stringer

ABSTRACT

A slide-fastener stringer having a pair of coupling elements mounted, for intermeshing upon movement of a slider therealong, upon juxtaposed edges of respective support tapes. The support tapes are each provided with a longitudinal row of openings for cooperation with the needle mechanism of an apparatus designed to attach the stringer to a garment or other fabric. The openings are formed by pushing back at least one warp thread extending parallel to the coupling element by thrusting a wedge-shaped needle or lance into the weave. A plurality of such lances may be provided in transversely staggered longitudinally spaced relation to force back the warp thread in successive stages.

United States Patent Inventor l-lelmut lleimberger Essen, Germany Appl.No. 824,524 Filed May 14, 1969 Patented Jan. 11, 1972 AssigneeOpti-Holding AG Glarus Schweiz, Germany Priority May 15, 1968 GermanyMETHOD OF MAKING A SLIDE-FASTENER STRINGER Primary ExaminerRobert R.Mackey Attorney- Karl F. Ross ABSTRACT: A slide-fastener stringer havinga pair of coupling elements mounted, for intermeshing upon movement of aslider therealong, upon juxtaposed edges of respective support tapes.The support tapes are each provided with a longitudinal row of openingsfor cooperation with the needle mechanism of an apparatus designed toattach the stringer to a garment or other fabric. The openings areformed by pushing back at least one warp thread extending parallel tothe coupling element by thrusting a wedge-shaped needle or lance intothe weave. A plurality of such lances may be provided in transverselystaggered longitudinally spaced relation to force back the warp threadin successive stages.

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BY m 7a ATTORNEY METHOD OF MAKING A SLIDE-FASTENER STRINGER My presentinvention relates to slide fasteners of the type in which a couplingelement is provided upon each of the mutually confronting edges of apair of support or carrier tapes or bands for intermeshing upon movementof a slider along the coupling elements in one direction and fordisengagement upon movement of the slider in the opposite direction;more particularly, the invention is directed to an arrangement forfacilitating the application of a separable slide fastener of this typeto a garment or other sheetlike member upon which the closure is to bemounted, and to a method of making the improved slide fastener and anapparatus for carrying out this method.

In my copending applications Ser. No. 562,877, filed July 5, 1966, nowUS. Pat. No. 3,488,239 granted Jan. 6, 1970, and Ser. No. 675,697, filedOct. 16, 1967, now US. Pat. No. 3,456,306 granted July 22, 1969 and myprior applications mentioned therein, there are described slide-fastenerclosures of the type in which continuous coupling elements are providedupon each of the confronting edges of a pair of parallel support tapesor hands, the coupling elements being helically coiled or undulatingmonofilamentary thermoplastic members in which each turn forms acoupling head receivable between the turns of the opposed couplingelement.

The coupling elements are generally stitched to the support tapes or areheld in place therein by passing the coupling heads of each elementthrough a respective opening formed between the threads of the fabric(knitted or woven) tape so that the threads of the latter tightly hugthe shanks of each coupling head and may be shrunk therearound to anchorthe coupling elements in place. In the most common practice, a core orfillet or bead of flexible material extends within or along the couplingelement and the latter is held in place by stitching the turns of thecoupling element and its fillet, core or bead in place by a single ordouble chain stitch which also has the function of accuratelypositioning the shanks and thereby separating the coupling heads. Thepresent invention is primarily concerned with slide-fastener stringersor stringer halves of this general type.

It has been proposed, in connection with separable slide fastenershaving woven or knitted fabric support tapes to form a longitudinal rowof openings alongside the coupling elements, i.e. parallel thereto, witha relatively uniform spacing such that the openings may cooperate withmembers of a stitching machine, e.g. the stitching needles, designed tomount each slide-fastener half upon a respective piece of underlyingmaterial, e.g. an edge of a garment or some other fabric article. It hasbeen the general practice heretofore to form these openings by weavingthem or knitting them in situ or by stamping them from a generallycontinuous support tape. Such operations have the important disadvantagethat the formation of the openings during the manufacture of the supporttape may lead to inaccuracy in the spacing of the openings, requiresexpensive machinery and highly skilled operating personnel, and cannotbe readily accommodated to changes in the spacing on the location ofthese openings. Similarly, stamping techniques may create inaccuracy,but have the more significant disadvantage that 'they greatly weaken thesupport tape at precisely the region in which greatest strength isrequired to take up the stresses applied to the closure, i.e. thelocation immediately adjoining the coupling elements.

It is, therefore, the principal object of the present invention toprovide an improved slide-fastener stringer, or stringer half, having alongitudinal array of uniformly spaced openings parallel to the couplingelement and free from the disadvantages of earlier systems, i.e. highcost, limited accuracy, and a tendency to weaken the region between thepoint at which the coupling element is affixed to the support tape andthe location at which the tape is secured to the substrate or fabricarticle.

Another object of my invention is the provision of an improved method ofmaking a slide-fastener stringer, or stringer half, in which thedisadvantages of earlier methods are avoided and the aforedescribed rowof longitudinally spaced openings can be formed with a minimum ofdifficulty, in a conveniently regulatable manner with respect to thesize and location of the openings and at relatively low cost.

Still another object of my instant invention is the provision of animproved apparatus for forming a longitudinal array of openings in aslide-fastener stringer or stringer half, which obviates the need forthe storage of quantities of tape with different numbers of rows of suchopenings, with a variety of interopening spacings, and with variouspositional differences of the array of openings.

These objects and others which will become apparent hereinafter areattained, in accordance with the present invention, by a system forforming a longitudinal array of openings in a support tape of aslide-fastener closure whereby one or more warp threads, extendingparallel to the edge of the support tape at which the coupling elementis or is to be situated, are thrust laterally, preferably away from thisedge and/or the coupling element, through a distance of about 1 mm. ormore, to form the row of openings without piercing or rupturing thedisplaced thread.

According to a more specific feature of this invention, the warp threadof the woven fabric tape is pushed to the side in a succession of stagesby the repeated and periodic insertion into the fabric of wedge-shapedneedles staggered progressively outwardly and one behind the latter inthe longitudinal direction, the support tape being advanced with respectto these needles. The thread-displacement needles may be mounted uponthe vertically reciprocable shank of a sewing machine whose pressurefoot bears upon the fabric tape in the region in which the needles arethrust through this tape.

The slide-fastener stringer, according to the present invention, thuscomprises two support tapes having mutually confronting longitudinaledges upon which are fastened respective continuous coupling elements ofthe aforedescribed type, the coupling elements being interengageable inthe usual manner upon movement of a slider of conventional constructiontherealong.

Each of the support tapes is formed with one or more rows of openingsand intervening strands of the fabric of the type to accommodatecooperating formations, members or needles of the stitching machinewhereby the tape is mounted upon a fabric or other member to be providedwith the slide-fastener closure.

The stringer, preferably with its coupling elements in an interlockedcondition, is advanced continuously or periodically past theopening-forming location at which respective arrays of wedge-shapedneedles, flanking the coupling elements on each side thereof, are thrustmomentarily through the support tapes with the aid of a sewing machinedrive to wedge respective warp threads laterally outwardly throughapproximately the distance between each pair of adjoining warp threads.The warp-thread-free zones constitute formations at which the supportbands are tied to the garment and cooperate with the needles of thebinding-off machine, i.e. enabling the support tape to be placed uponthe needles of the latter machine. As noted earlier, these longitudinalarrays of openings or warpfree zones lie directly adjacent eachrespective coupling elements, each wedging needle having along the sidefacing the coupling element, a flank extending perpendicular to thesupport tape while its flank facing away from the coupling elementdiverges outwardly from the vertical or perpendicular flank.

Such an arrangement has numerous significant advantages. Thus, thearticle to which the tape is to be secured, is no longer covereddirectly adjacent coupling elements and attachment of the tape to thearticle is facilitated. Of even greater significance is the fact thatthe row along which the warp thread has been pushed aside, permits thetape to be applied to the bank of a binding-off machine of the typeheretofore used for interlacing the article and the support tape withgreater ease. Such machines generally have an array of needles adaptedto extend through the openings provided in the support tape. The arrayof openings provided by lateral shifting ofa warp thread, in accordancewith the present invention, enables the tape to be mounted on this arrayof needles with great facility. Surprisingly, the shift of the warpthread in accordance with the present invention has been found to beadvantageous also in that the warp thread tends to remain in its shiftedposition and the band or tape can be displaced, stored or otherwisehandled without any danger that the openings thus provided will close bya return of the warp thread to its original position. Of specialsignificance is the fact that the formation of the openings or theneedle-accommodating row, according to the present invention, can beeffected with ease, without weakening of the fabric tape, can be formedclose to the coupling elements and, as a practical matter, can have anydesirable width, e.g. from one to several millimeters. The asymmetricallances or needles, which serve to displace the warp thread, can beconveniently mounted on a sewing machine ram, can be provided in anydesirable number and with any desirable spacing, and can have roundedends of a width such that they do not pierce the threads.Advantageously, they are spaced apart in the direction of advance of theband by approximately the spacing of the weft threads and, as viewed inthe direction of movement of the band, laterally overlap.

The above and other objects, features and advantages ofthe presentinvention will become more readily apparent from the followingdescription, reference being made to the accompanying drawing in which:

FIG. 1 is a perspective view of a slide-fastener stringer embodying thepresent invention;

FIG. 1A is a detail view drawn to an enlarged scale ofa region of FIG.1;

FIG. 1B is a view similar to FIG. 1A of another stringer portion mountedupon an article;

FIG. 2 is an end view of the apparatus for shifting the warp thread inaccordance with the present invention, the stringer being shown in crosssection in a plane perpendicular to its longitudinal direction;

FIG. 3 is a side view of the apparatus of FIG. 2; and

FIG. 4 is a diagrammatic illustration showing how the wedge-shapedneedles or lances of the present invention displace the warp thread.

In FIGS. 1 and LA, I have shown a slide-fastener stringer, the slider ofwhich may be of any conventional type and which may be provided withend-stop members as described in the aforementioned copendingapplications and which comprises a pair of woven support tapes 1 and 2,whose confronting edges la and 2a, are formed with respective couplingelements 3, 4 whose heads are interfitted as shown in FIG. 1 and whichare anchored to the support tapes by rows 31: (FIG. 1) and 4a of chainstitches which are looped over the shanks (e.g. 4b of FIG. 1A) and whichextend through respective fillets 3c and 4c received within the helicalcoupling elements. The coupling elements are here shown as flattenedhelices of a nylon-type monofilamentary synthetic resin (see theaforementioned applications) and can be any conventional continuouscoupling elements, e.g. coupling elements of the undulated type as well.

Along the coupling elements 3, 4 and flanking them but close to thebights 4d, there are provided longitudinally extending rows of couplingformations 5 enabling the respective support tapes to be bound into afabric after being placed upon the needles of the bind-off machine, inthe usual manner. A woven fabric substrate is shown at F in FIG. 1B andhas thread loops L extending around the stretches 7a of weft threads inthe respective arrays to secure the tape 2 to the article F.

As is illustrated in detail in FIG. 1A, the fabric tape 2 is composed ofa set of transversely extending, equispaced weft threads 7 interweavedwith the warp threads 6 which extend parallel to the coupling elementsand orthogonally to the weft 7. A warp thread 6a is shifted from itsnormal position to the right (FIG. 1A) to form the array 5 of theneedle-receiving openings 5a spaced apart by the strips 7a of the weft7. The

warp thread 60 bears against the adjacent thread 6b which, in turn, hasbeen shifted slightly to the right toward the thread 60. A thread 6d,unmoved in the process of shifting thread 6a, defines the left-handboundary of the array 5. From FIG. 18 it can be seen that two arrays 5and 5' are provided in the fabric band 2' carrying the coupling element4 which is held in place by the chain stitch 4a through the core 4c. Theloops L and L bind the tape 2' to the underlying fabric F.

The warp-free zones 5 and 5 thus constitute arrays of openings 5a whichcan be thrust onto the needles ofa bind-off machine. The thread 6a maybe shifted away from the coupling element 4 to a distance d of, say, lto 4 mm.

In FIGS. 2-4, I show the apparatus for forming the warpfree zones 5 ofFIGS. 1, IA and 1B. The apparatus comprises a sewing machine ram orspindle 15 which is vertically reciprocable by the sewing machine driverepresented at 16 and as indicated by the arrow 17a.

The band 1, 2, is held down by a pressure foot 17 while the band isadvanced to the left past the lance location as represented by the arrow18 via a feed device shown in FIG. 3. The feed device comprises aweighted sprocket wheel 19 engageable with the turns of the couplingelements 3, 4 and rotated periodically in the clockwise sense (arrow 20)by a reciprocating pawl 21 whose motion is represented by the arrow 22and which is coupled with the sewing-machine drive As shown in FIG. 3,three longitudinally offset needles l0, 9, 8 serve to displace thethread 6a through the desired dim ension, exaggerated in FIG. 2 andrepresented by the dimension D, the needles 8, 9, l0 overlappingsuccessively when viewed from the end (FIG. 2). The needles aretransversely staggered (FIG. 2) and are of lance configuration withslightly rounded points receivable between each pair of adjacent warpand each pair of adjacent weft threads.

The lances each have a straight flank 23 extending vertically (FIG. 2)and perpendicular to the plane of the fabric (FIG. 4) as well as a flank12 inclined to this perpendicular flank inwardly with respect to thecoupling element in the direction in which the lance is thrust throughthe fabric. The width w of the rounded tip 11 of each lance is less thanthe normal center-to-center spacing S of the warp thread 6a while thebase of the wedge has a width W exceeding the interthread spacing anddesigned to push the thread 6a to the right (FIG. 4). Upon withdrawal ofthe shank k of lances 8-10, the stringer is advanced to the left for asuccessive operation in which the lances engage the thread 6a and pushit further to the right (FIG. 4).

Iclaim:

1. In a method of making a slide-fastener assembly in which a pair ofwoven-fabric support tapes have juxtaposed edges each provided with alongitudinally extending coupling element engageable with the couplingelement of the other tape and with longitudinally extending warp threadsinterwoven with transversely extending weft threads and the supporttapes are interlaced with fabric on a binding-off machine having anarray of needles, the improvement which comprises the steps of:

a. advancing said support tapes along a transport path in incrementscorresponding to the spacing between the weft threads; and

b. thrusting a wedge member having a row of wedge elements between theadjacent weft threads to displace at least one of the wrap threads outofits original position to form openings accommodating said needles uponeach increment of displacement of said tapes, said wedge elements ofsaid row being offset in the longitudinal direction and having wedgingsurfaces successively spaced at greater distances from the couplingelement and thrust simultaneously between the respective pairs of weftthreads to shift said warp thread in a plurality of stages.

2. The method defined in claim 1 wherein said warp thread is the warpthread immediately adjacent the coupling element.

3. The method defined in claim 1 wherein said wedge elements each have aflank parallel to the direction in which the wedge elements are thrustthrough said tapes and a wedge surface inclined thereto and convergingin the thrust direction.

1. In a method of making a slide-fastener assembly in which a pair ofwoven-fabric support tapes have juxtaposed edges each provided with alongitudinally extending coupling element engageable with the couplingelement of the other tape and with longitudinally extending warp threadsinterwoven with transversely extending weft threads and the supporttapes are interlaced with fabric on a binding-off machine having anarray of needles, the improvement which comprises the steps of: a.advancing said support tapes along a transport path in incrementscorresponding to the spacing between the weft threads; and b. thrustinga wedge member having a row of wedge elements between the adjacent weftthreads to displace at least one of the wrap threads out of its originalposition to form openings accommodating said needles upon each incrementof displacement of said tapes, said wedge elements of said row beingoffset in the longitudinal direction and having wedging surfacessuccessively spaced at greater distances from the coupling element andthrust simultaneously between the respective pairs of weft threads toshift said warp thread in a plurality of stages.
 2. The method definedin claim 1 wherein said warp thread is the warp thread immediatelyadjacent the coupling element.
 3. The method defined in claim 1 whereinsaid wedge elements each have a flank parallel to the direction in whichthe wedge elements are thrust through said tapes and a wedge surfaceinclined thereto and converging in the thrust direction.